Ige explanation? and an allergist’s explanation of my allergies

I thought the allergy blood test that gives the IgE results was a test of WHAT you are allergic to…i.e. a running list of those things you are allergic to. My very soon to be former allergist(!) says that the test is designed to show what allergens someone is currently reacting to and how badly they are reacting. Is she right? So, conceivably your IgE numbers would change as you come in and out of contact with an allergen – correct? Also, if she is correct, and my IgE shows that I am reacting to many allergens, how would an allergist know which allergen is causing the current allergic reactions?

I have asked this before, but I'm not sure if I was clear. The allergist said that someone can be allergic to something and NEVER have a reaction to it. But if that person comes in contact with something, (i.e. a chemical), that chemical can 'trigger' your body to now always having an allergic reaction (i.e. the typical itchy/watery eyes, stinging tongue and throat, warm hands, etc., etc.) when coming into contact with your allergens. Has anyone been told that by their allergists? Is she right? It sounds dubious to me, but then I am not a doctor.

As always, thank you so much for your continuing support, concern and help! Very, very much appreciated.


Comments 12

  • LK

    Hi Paularose,  Those are good questions. 

    I have just started on Xolair and have been trying to learn as much as I can about allergic asthma.   

    As far as the IgE test, my understanding is it shows what you are allergic to. IgE is always present in your body in small amounts.  I found this information on the Mayo Clinic website - 

    "Anti-immunoglobulin E (IgE) therapy. When you have an allergy, your immune system mistakenly identifies a specific substance as something harmful and releases antibodies, known as IgE, against the culprit allergen.

    The next time you encounter that allergen, the IgE antibodies sense it and signal your immune system to release a chemical called histamine, as well as other chemicals, into your bloodstream. The medication omalizumab (Xolair) interferes with IgE in the body and helps prevent the allergic reaction that triggers asthma symptoms."

    "Blood test. Specific IgE (sIgE) blood testing, commonly called radioallergosorbent test (RAST) or ImmunoCAP testing, measures the amount of allergy-causing antibodies in your bloodstream, known as immunoglobulin E (IgE) antibodies. A blood sample is sent to a medical laboratory, where it can be tested for evidence of sensitivity to possible allergens."

    You may already have read these articles.  I found them helpful.  I am still learning about my asthma and now allergic asthma so will be interested to read what you find out.

  • Paularose

    Thank you so much Lisa for your reply. I will definitely post if I find anything helpful.


  • Shea

    I don't know all the science by any means– but I do look at the tests more like clues– and you've gotta get all the evidence together to solve the mystery. 

    One thing I have learned is not all allergies are IgE-mediated. According to an article from  (   )

    "Immediate reactions to food antigens are IgE-mediated and dependent on activation of mast cells in specific tissues, including the skin, respiratory tract, gastrointestinal, mucosal, and cardiovascular system [-].

    The delayed immune reaction to food antigens are mediated by IgG, IgA and IgM. Unlike the immediate effects of IgE-mediated allergy, the IgG, IgM and IgA-mediated food allergy and intolerance reactions can take several days to appear. Therefore, levels of IgG, IgM and IgA antibodies in the blood against different food antigens have been used for demonstration of delayed food allergy and intolerance reactions [,]."


    So keep that in mind if you have a negative to something you think is bothering you. 

    Once I had an IgE blood test come negative and a skin test positive… And I KNEW I was allergic to the thing… I had big reactions to it on many occasions. So definitely trust your journals and self too when putting your clues together. 




  • LK

    Shea,  That is very interesting how some reactions may take days to appear.

  • Brenda Silvia-Torma

    @Paularose, Hello! I found this link and thought it might be helpful regarding your question about IgE and food allergy testing.

    Hope this info helps!


  • Naresh


    I have been experiencing rashes on fore hands and legs after eating chicken and eggs. Please suggest the treatment for this & also let me know if this is  chronic .

  • K8sMom2002

    Naresh, hi, and welcome! That sounds really frustrating! If you have rashes after eating foods, it could be the sign of a food allergy. Could you see an allergist? 

    Here's a link to  to explain more about severe allergic reaction. It's on Kids With Food Allergies, AAFA's food allergy division. KFA's resource on  might help you as well.

  • Melissa G

    @Naresh Hi and Welcome to AAFA! I am sorry you are having rashes after eating chicken and eggs. I agree with Cynthia, I would make an appt with allergist and see what they recommend. 

  • Shea

    Hi Naresh. I third that notion on the allergist. If it is allergy to chicken and eggs then the allergist can give you emergency medication in case the reactions get worse (like an epipen which saves lives if the allergic reaction develops into anaphlaxis). They can also help you identify signs of allergy and how to treat them, and confirm what is causing the allergy. One thing I have learned is dont mess with allergies because they can be very serious. My peanut allergic reactions started mild but got worse with each accidental ingestion and now I am highly anaphlactic and having my epipen with me has saved my life. My son has had some reaction to chicken and same with his father so we avoid eating it after talking with the allergist (although he can eat eggs fine). 

  • K8sMom2002

    @Paularose, were you ever able to find an allergist you were comfortable with and the answers to your questions? I hope you were! I can't imaging managing asthma and allergies without a board-certified allergist on our team!

    Naresh, I am so hoping that you can get some answers from your allergist as well. Shea's right — food allergies are something to take very seriously.

  • Paularose

    Cynthia, still have not found an allergist who I can trust. Have appointment with another one Friday.

  • Melissa G

    Paula I am so sorry you have not been able to find an allergist you can trust! Good luck on Friday and keep us posted on how the appt goes.